DAC7678_10 Datasheet, PDF (29/52 Pages) Texas Instruments – 12-Bit, Octal-Channel, Ultra-Low Glitch, Voltage Output, Two-Wire Interface Digital-to-Analog Converter with 2.5V Internal Reference

DAC7678
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Command and Access (CA) Byte
The Command and Access Byte, as shown in
Table 11, controls which command is executed and
which register is being accessed when writing to or
reading from the DAC7678. See Table 12 for a list of
write and read commands.
SBAS493A – FEBRUARY 2010 – REVISED AUGUST 2010
Table 11. Command and Access Byte
MSB
LSB
C3 C2 C1 C0 A3 A2 A1 A0
Command bits
Access bits
Table 12. Command and Access Byte Format⁽¹⁾
C3 C2 C1 C0 A3 A2 A1 A0
DESCRIPTION
Write Sequences
0
0
0
0 A3 A2 A1 A0 Write to DAC input register channel n
0
0
0
1 A3 A2 A1 A0 Select to update DAC register channel n
0
0
1
0
A3
A2
A1
A0
Write to DAC input register channel n, and update all DAC registers (global
software LDAC)
0
0
1
1 A3 A2 A1 A0 Write to DAC input register channel n, and update DAC register channel n
0
1
0
0
X
X
X
X Power down/on DAC
0
1
0
1
X
X
X
X Write to clear code register
0
1
1
0
X
X
X
X Write to LDAC register
0
1
1
1
X
X
X
X Software reset
1
0
0
0
X
X
X
X Write to internal reference register
1
0
0
1
X
X
X
X Write to additional internal reference register
Read Sequences
0
0
0
0 A3 A2 A1 A0 Read from DAC input register channel n
0
0
0
1 A3 A2 A1 A0 Read from DAC register channel n
0
1
0
0
X
X
X
X Read from DAC power down register
0
1
0
1
X
X
X
X Read from clear code register
0
1
1
0
X
X
X
X Read from LDAC register
1
0
0
0
X
X
X
X Read from internal reference register
1
0
0
1
X
X
X
X Read from additional internal reference register
Access Sequences
C3 C2 C1 C0 0
0
0
0 DAC channel A
C3 C2 C1 C0 0
0
0
1 DAC channel B
C3 C2 C1 C0 0
0
1
0 DAC channel C
C3 C2 C1 C0 0
0
1
1 DAC channel D
C3 C2 C1 C0 0
1
0
0 DAC channel E
C3 C2 C1 C0 0
1
0
1 DAC channel F
C3 C2 C1 C0 0
1
1
0 DAC channel G
C3 C2 C1 C0 0
1
1
1 DAC channel H
C3 C2 C1 C0 1
1
1
1 All DAC channels, broadcast update
(1) Any sequences other than the ones listed are invalid; improper use can cause incorrect device functionality.
Most Significant Data Byte (MSDB) and Least
Significant Data Byte (LSDB)
shown in Table 13 and Table 14. See Table 17 for a
complete list of write sequences and Table 18 for a
complete list of read sequences. The DAC7678
The MSDB and LSDB contain the data that are
passed to the register(s) specified by the CA byte, as
updates at the falling edge of the acknowledge signal
that follows the LSDB[0] bit.
Table 13. MSDB
MSB
LSB
DB15
DB14
DB13
DB12
DB11
DB10
DB9
DB8
Most Significant Data Byte (MSDB)
Copyright © 2010, Texas Instruments Incorporated
Product Folder Link(s): DAC7678
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